condition mean min max 4 h after light 6.62257 6.5118599999999995 6.717230000000001 8 h after light 6.7442400000000005 6.65451 6.81663 12 h after light 6.52196 6.34607 6.78298 4 h after dark 6.691493333333334 6.54743 6.9256899999999995 8 h after dark 6.523146666666667 6.4134400000000005 6.66052 12 h after dark 6.537 6.41505 6.600569999999999